From 31bc3478673032779b4031a664444820f71e9fa1 Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Wed, 25 Sep 2024 22:38:41 +0200
Subject: [PATCH 01/12] Define device and volume classes OOP-style

---
 dm-sflc/src/sflc_types.h | 154 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 dm-sflc/src/sflc_types.h

diff --git a/dm-sflc/src/sflc_types.h b/dm-sflc/src/sflc_types.h
new file mode 100644
index 0000000..4ae0ab6
--- /dev/null
+++ b/dm-sflc/src/sflc_types.h
@@ -0,0 +1,154 @@
+/*
+ *  Copyright The Shufflecake Project Authors (2022)
+ *  Copyright The Shufflecake Project Contributors (2022)
+ *  Copyright Contributors to the The Shufflecake Project.
+ *  
+ *  See the AUTHORS file at the top-level directory of this distribution and at
+ *  <https://www.shufflecake.net/permalinks/shufflecake-userland/AUTHORS>
+ *  
+ *  This file is part of the program shufflecake-c, which is part of the
+ *  Shufflecake Project. Shufflecake is a plausible deniability (hidden storage)
+ *  layer for Linux. See <https://www.shufflecake.net>.
+ *  
+ *  This program is free software: you can redistribute it and/or modify it 
+ *  under the terms of the GNU General Public License as published by the Free 
+ *  Software Foundation, either version 2 of the License, or (at your option) 
+ *  any later version. This program is distributed in the hope that it will be 
+ *  useful, but WITHOUT ANY WARRANTY; without even the implied warranty of 
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 
+ *  Public License for more details. You should have received a copy of the 
+ *  GNU General Public License along with this program. 
+ *  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * This kernel module implements Shufflecake as an in-kernel device driver,
+ * built on top of the device-mapper framework.
+ * Shufflecake supports several "modes" (currently Legacy and Lite). Each mode
+ * is a distinct set of algorithms which implements a specific flavour of the
+ * Shufflecake scheme; they are very different and largely incompatible with
+ * each other. For this reason, each mode has its own independent, complete
+ * implementation - located in a subdirectory of the root - and exposes a
+ * standardised interface to the top-level "dispatcher", which only takes care
+ * of the few bookkeeping tasks which are common to all modes, and displays a
+ * unified view to user space through the sysfs.
+ *
+ * In order to achieve an intuitive and maintainable separation between the
+ * dispatcher and the modes, a "lightweight" OOP-style coding convention is
+ * followed: not fully general, but just enough to allow for one-level class
+ * inheritance and type-checked method polymorphism.
+ * Base "classes" exist to represent devices and volumes (see Shufflecake docs
+ * to learn what these terms mean): they are structs containing the fields
+ * needed by the dispatcher for its bookkeeping. Derived "classes" exist to
+ * represent mode-specific devices and volumes: they are structs embedding a
+ * base-class struct "by-value", plus their own specific fields.
+ * Type-checked polymorphism is achieved by having device and volume methods
+ * take as argument a pointer to a base-class struct, instead of an opaque void
+ * pointer. The pointer is then "down-cast" in the mode-specific method.
+ */
+
+#ifndef _SFLC_TYPES_H
+#define _SFLC_TYPES_H
+
+
+#include <linux/device-mapper.h>
+
+#include "sflc_constants.h"
+#include "legacy/sflc_legacy.h"
+#include "lite/sflc_lite.h"
+
+
+/*
+ *----------------------------
+ * Structs
+ *----------------------------
+ */
+
+/**
+ * The virtual table.
+ * Contains all the concrete method pointers provided by a Shufflecake mode
+ * (devices + volumes + devmapper).
+ * It is a field in the base class, but will be set by the constructor of the
+ * derived class.
+ */
+struct sflc_mode_ops;
+
+/**
+ * Base class for devices.
+ * It is inherited by derived classes for mode-specific devices.
+ */
+struct sflc_device_base
+{
+	/* Shufflecake-unique device ID */
+	u32			dev_id;
+	/* <MAJOR>:<MINOR> */
+	char			name[16];
+	/* Shufflecake mode: legacy/lite */
+	int			mode;
+	/* Number of (open) volumes */
+	u32			nr_volumes;
+
+	/* Sysfs */
+	struct kobject		kobj;
+	struct completion	kobj_released;
+
+	/* Virtual table */
+	struct sflc_mode_ops	*ops;
+};
+
+/**
+ * Base class for volumes.
+ * It is inherited by derived classes for mode-specific volumes.
+ */
+struct sflc_volume_base
+{
+	/* Backing device */
+	struct sflc_device	*sdev;
+	/* Volume name: sflc_<devID>_<volIdx> */
+	char			name[32];
+
+	/* Sysfs */
+	struct kobject		kobj;
+	struct completion	kobj_released;
+
+	/* Virtual table */
+	struct sflc_mode_ops	*ops;
+};
+
+
+/*
+ *----------------------------
+ * Methods
+ *----------------------------
+ */
+
+/* Device constructor */
+typedef struct sflc_device_base* (*sflc_mode_dev_ctr_fn) (
+		struct dm_target *ti, int argc, char **argv);
+/* Device destructor */
+typedef void (*sflc_mode_dev_dtr_fn) (struct sflc_device_base* sd_base);
+
+/* Volume constructor */
+typedef struct sflc_volume_base* (*sflc_mode_vol_ctr_fn) (
+		struct sflc_device_base *sd_base, struct dm_target *ti,
+		int argc, char **argv);
+/* Volume destructor */
+typedef void (*sflc_mode_vol_dtr_fn) (struct sflc_volume_base* sv_base);
+
+/**
+ * A Shufflecake mode must provide ctr() and dtr() for devices and volumes,
+ * as well as devmapper-related methods.
+ */
+struct sflc_mode_ops
+{
+	sflc_mode_dev_ctr_fn	dev_ctr;
+	sflc_mode_dev_dtr_fn	dev_dtr;
+	sflc_mode_vol_ctr_fn	vol_ctr;
+	sflc_mode_vol_dtr_fn	vol_dtr;
+	dm_map_fn		map;
+	dm_io_hints_fn		io_hints;
+	dm_iterate_devices_fn	iterate_devices;
+};
+
+
+#endif	/* _SFLC_TYPES_H */

From e27f738260fbd70347fc391c9ef325e6400b602f Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Fri, 27 Sep 2024 00:05:54 +0200
Subject: [PATCH 02/12] Minor adjustments

---
 dm-sflc/src/sflc.h       | 82 ++++++++++------------------------------
 dm-sflc/src/sflc_types.h |  2 +-
 2 files changed, 20 insertions(+), 64 deletions(-)

diff --git a/dm-sflc/src/sflc.h b/dm-sflc/src/sflc.h
index 1ff8499..896c43e 100644
--- a/dm-sflc/src/sflc.h
+++ b/dm-sflc/src/sflc.h
@@ -27,58 +27,8 @@
 
 #include <linux/device-mapper.h>
 
+#include "sflc_types.h"
 #include "sflc_constants.h"
-#include "legacy/sflc_legacy.h"
-#include "lite/sflc_lite.h"
-
-
-/*
- *----------------------------
- * Structs
- *----------------------------
- */
-
-struct sflc_device
-{
-	/* Shufflecake-unique device ID */
-	u32			dev_id;
-	/* <MAJOR>:<MINOR> */
-	char			name[16];
-	/* Number of volumes */
-	u32			nr_volumes;
-
-	/* Mode-specific device struct */
-	int			mode;
-	union {
-		sflegc_Device		*sflegc_dev;
-		struct sflite_device	*sflite_dev;
-	};
-
-	/* Sysfs */
-	struct kobject		kobj;
-	struct completion	kobj_released;
-};
-
-struct sflc_volume
-{
-	/* Backing device */
-	struct sflc_device	*sdev;
-	/* Volume name: sflc_<devID>_<volIdx> */
-	char			name[32];
-
-	/* Mode-specific volume struct */
-	int			mode;
-	union {
-		sflegc_Volume		*sflegc_vol;
-		struct sflite_volume	*sflite_vol;
-	};
-	/* Pointers to concrete, mode-specific callbacks */
-	struct target_type	*tt;
-
-	/* Sysfs */
-	struct kobject		kobj;
-	struct completion	kobj_released;
-};
 
 
 /*
@@ -87,8 +37,12 @@ struct sflc_volume
  *----------------------------
  */
 
+/* Every mode provides a full set of algorithms */
+struct sflc_mode_ops **sflc_mode_ops;
+
+/* Array of all open devices */
 extern struct mutex sflc_alldevs_lock;
-extern struct sflc_device **sflc_alldevs;
+extern struct sflc_device_base **sflc_alldevs;
 /* Next free device id */
 extern u32 sflc_free_devid;	/* The lowest free devID */
 
@@ -99,22 +53,24 @@ extern u32 sflc_free_devid;	/* The lowest free devID */
  *----------------------------
  */
 
-/* Device */
-struct sflc_device *sflc_dev_create(struct dm_target *ti, int argc, char **argv);
-void sflc_dev_destroy(struct sflc_device *sdev);
+/* Device base */
+int sflc_dev_base_init(struct sflc_device_base *sd_base, struct dm_target *ti,
+		    int argc, char **argv);
+void sflc_dev_base_exit(struct sflc_device_base *sd_base);
 
-/* Volume */
-struct sflc_volume *sflc_vol_create(struct sflc_device *sdev, struct dm_target *ti,
-		int argc, char **argv);
-void sflc_vol_destroy(struct sflc_volume *svol);
+/* Volume base */
+int sflc_vol_base_init(struct sflc_volume *sv_base,
+			 struct sflc_device_base *sd_base, struct dm_target *ti,
+			 int argc, char **argv);
+void sflc_vol_base_exit(struct sflc_volume_base *sv_base);
 
 /* Sysfs */
 int sflc_sysfs_init(void);
 void sflc_sysfs_exit(void);
-int sflc_sysfs_register_device(struct sflc_device *sdev);
-void sflc_sysfs_unregister_device(struct sflc_device *sdev);
-int sflc_sysfs_register_volume(struct sflc_volume *svol);
-void sflc_sysfs_unregister_volume(struct sflc_volume *svol);
+int sflc_sysfs_register_device_base(struct sflc_device_base *sd_base);
+void sflc_sysfs_unregister_device_base(struct sflc_device_base *sd_base);
+int sflc_sysfs_register_volume_base(struct sflc_volume_base *sv_base);
+void sflc_sysfs_unregister_volume_base(struct sflc_volume_base *sv_base);
 
 
 #endif	/* _SFLC_H */
diff --git a/dm-sflc/src/sflc_types.h b/dm-sflc/src/sflc_types.h
index 4ae0ab6..5d7347e 100644
--- a/dm-sflc/src/sflc_types.h
+++ b/dm-sflc/src/sflc_types.h
@@ -84,7 +84,7 @@ struct sflc_device_base
 	/* <MAJOR>:<MINOR> */
 	char			name[16];
 	/* Shufflecake mode: legacy/lite */
-	int			mode;
+	u32			mode;
 	/* Number of (open) volumes */
 	u32			nr_volumes;
 

From c0824a6a2d950653d3c1af11fe49fb95e9b0337d Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Fri, 27 Sep 2024 21:29:29 +0200
Subject: [PATCH 03/12] Adapt dev_vol.c

---
 dm-sflc/src/dev_vol.c    | 173 +++++++--------------------------------
 dm-sflc/src/sflc.h       |   8 +-
 dm-sflc/src/sflc_types.h |   2 +-
 3 files changed, 34 insertions(+), 149 deletions(-)

diff --git a/dm-sflc/src/dev_vol.c b/dm-sflc/src/dev_vol.c
index 6c454b9..2fc94b3 100644
--- a/dm-sflc/src/dev_vol.c
+++ b/dm-sflc/src/dev_vol.c
@@ -27,183 +27,68 @@
 #include "legacy/sflc_legacy.h"
 
 
-/* Create a sflc_device containing the appropriate mode-specific struct */
-struct sflc_device *sflc_dev_create(struct dm_target *ti, int argc, char **argv)
+/* Init a sflc_device_base */
+int sflc_dev_base_init(struct sflc_device_base *sd_base, struct dm_target *ti,
+		       int argc, char **argv)
 {
-	struct sflc_device *sdev;
 	u32 dev_id;
 	dev_t devt;
-	int mode;
 	int err;
 
-	sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
-	if (!sdev) {
-		DMERR("Could not allocate device");
-		return ERR_PTR(-ENOMEM);
-	}
-
 	/* Parse arguments */
-	if (sscanf(argv[0], "%d", &mode) != 1) {
-		err = -EINVAL;
-		goto bad_parse;
-	}
+	if (sscanf(argv[0], "%d", &mode) != 1)
+		return -EINVAL;
 	sscanf(argv[1], "%u", &dev_id);
 	err = lookup_bdev(argv[2], &devt);
-	if (err) {
-		DMERR("Could not look up block device");
-		goto bad_parse;
-	}
+	if (err)
+		return err;
 
 	/* Assign fields */
-	sdev->dev_id = dev_id;
-	sdev->nr_volumes = 0;
-	sdev->mode = mode;
-	format_dev_t(sdev->name, devt);
+	sd_base->dev_id = dev_id;
+	sd_base->nr_volumes = 0;
+	format_dev_t(sd_base->name, devt);
+	/* Fields `mode` and `ops` will be set by the derived constructor */
 
 	/* Register with sysfs */
-	err = sflc_sysfs_register_device(sdev);
+	err = sflc_sysfs_register_device_base(sd_base);
 	if (err)
-		goto bad_sysfs;
+		return err;
 
-	/* Instantiate inner device. Sysfs has to be inited by now */
-	switch (mode)
-	{
-	case SFLC_MODE_LEGACY:
-		sdev->sflegc_dev = sflegc_dev_create(ti, argc, argv, &sdev->kobj);
-		if (IS_ERR(sdev->sflegc_dev)) {
-			err = PTR_ERR(sdev->sflegc_dev);
-			goto bad_inner;
-		}
-		break;
-	case SFLC_MODE_LITE:
-		sdev->sflite_dev = sflite_dev_create(ti, argc, argv, &sdev->kobj);
-		if (IS_ERR(sdev->sflite_dev)) {
-			err = PTR_ERR(sdev->sflite_dev);
-			goto bad_inner;
-		}
-		break;
-	default:
-		DMERR("Invalid Shufflecake mode %d", mode);
-		err = -EINVAL;
-		goto bad_mode;
-	}
-
-	return sdev;
-
-
-bad_mode:
-bad_inner:
-	sflc_sysfs_unregister_device(sdev);
-bad_sysfs:
-bad_parse:
-	kfree(sdev);
-	return ERR_PTR(err);
+	return 0;
 }
 
 
-void sflc_dev_destroy(struct sflc_device *sdev)
+void sflc_dev_base_exit(struct sflc_device_base *sd_base)
 {
-	switch (sdev->mode)
-	{
-	case SFLC_MODE_LEGACY:
-		sflegc_dev_destroy(sdev->sflegc_dev);
-		break;
-	case SFLC_MODE_LITE:
-		sflite_dev_destroy(sdev->sflite_dev);
-		break;
-	default:
-		DMCRIT("Destroying device with invalid Shufflecake mode %d", sdev->mode);
-		return;
-	}
-
-	sflc_sysfs_unregister_device(sdev);
-	kfree(sdev);
+	sflc_sysfs_unregister_device_base(sd_base);
 }
 
-/* Create a sflc_volume containing the appropriate mode-specific struct */
-struct sflc_volume *sflc_vol_create(struct sflc_device *sdev, struct dm_target *ti,
-		int argc, char **argv)
+/* Init a sflc_volume_base */
+int sflc_vol_base_init(struct sflc_volume_base *sv_base,
+		       struct sflc_device_base *sd_base, struct dm_target *ti,
+		       int argc, char **argv)
 {
-	struct sflc_volume *svol;
 	u32 vol_idx;
-	int mode;
 	int err;
 
-	svol = kzalloc(sizeof(*svol), GFP_KERNEL);
-	if (!svol) {
-		DMERR("Could not allocate volume");
-		return ERR_PTR(-ENOMEM);
-	}
-
 	/* Parse arguments */
-	if (sscanf(argv[0], "%d", &mode) != 1) {
-		err = -EINVAL;
-		goto bad_parse;
-	}
 	sscanf(argv[3], "%u", &vol_idx);
 
 	/* Assign fields */
-	svol->mode = mode;
-	sprintf(svol->name, "sflc_%u_%u", sdev->dev_id, vol_idx);
-	svol->sdev = sdev;
+	sprintf(sv_base->name, "sflc_%u_%u", sd_base->dev_id, vol_idx);
+	sv_base->sd_base = sd_base;
+	/* Field `ops` will be set by the derived constructor */
 
 	/* Register with sysfs */
-	err = sflc_sysfs_register_volume(svol);
+	err = sflc_sysfs_register_volume_base(sv_base);
 	if (err)
-		goto bad_sysfs;
+		return err;
 
-	/* Instantiate inner volume. Sysfs has to be inited by now */
-	switch (mode)
-	{
-	case SFLC_MODE_LEGACY:
-		svol->sflegc_vol = sflegc_vol_create(ti, sdev->sflegc_dev, argc, argv, &svol->kobj);
-		if (IS_ERR(svol->sflegc_vol)) {
-			err = PTR_ERR(svol->sflegc_vol);
-			goto bad_inner;
-		}
-		svol->tt = &sflegc_target_type;
-		break;
-	case SFLC_MODE_LITE:
-		svol->sflite_vol = sflite_vol_create(ti, sdev->sflite_dev, argc, argv, &svol->kobj);
-		if (IS_ERR(svol->sflite_vol)) {
-			err = PTR_ERR(svol->sflite_vol);
-			goto bad_inner;
-		}
-		svol->tt = &sflite_target_type;
-		break;
-	default:
-		DMERR("Invalid Shufflecake mode %d", mode);
-		err = -EINVAL;
-		goto bad_mode;
-	}
-
-	return svol;
-
-
-bad_mode:
-bad_inner:
-	sflc_sysfs_unregister_volume(svol);
-bad_sysfs:
-bad_parse:
-	kfree(svol);
-	return ERR_PTR(err);
+	return 0;
 }
 
-void sflc_vol_destroy(struct sflc_volume *svol)
+void sflc_vol_base_exit(struct sflc_volume_base *sv_base)
 {
-	switch (svol->mode)
-	{
-	case SFLC_MODE_LEGACY:
-		sflegc_vol_destroy(svol->sflegc_vol);
-		break;
-	case SFLC_MODE_LITE:
-		sflite_vol_destroy(svol->sflite_vol);
-		break;
-	default:
-		DMCRIT("Destroying volume with invalid Shufflecake mode %d", svol->mode);
-		return;
-	}
-
-	sflc_sysfs_unregister_volume(svol);
-	kfree(svol);
+	sflc_sysfs_unregister_volume_base(sv_base);
 }
+
diff --git a/dm-sflc/src/sflc.h b/dm-sflc/src/sflc.h
index 896c43e..ed206c1 100644
--- a/dm-sflc/src/sflc.h
+++ b/dm-sflc/src/sflc.h
@@ -55,13 +55,13 @@ extern u32 sflc_free_devid;	/* The lowest free devID */
 
 /* Device base */
 int sflc_dev_base_init(struct sflc_device_base *sd_base, struct dm_target *ti,
-		    int argc, char **argv);
+		       int argc, char **argv);
 void sflc_dev_base_exit(struct sflc_device_base *sd_base);
 
 /* Volume base */
-int sflc_vol_base_init(struct sflc_volume *sv_base,
-			 struct sflc_device_base *sd_base, struct dm_target *ti,
-			 int argc, char **argv);
+int sflc_vol_base_init(struct sflc_volume_base *sv_base,
+		       struct sflc_device_base *sd_base, struct dm_target *ti,
+		       int argc, char **argv);
 void sflc_vol_base_exit(struct sflc_volume_base *sv_base);
 
 /* Sysfs */
diff --git a/dm-sflc/src/sflc_types.h b/dm-sflc/src/sflc_types.h
index 5d7347e..e866013 100644
--- a/dm-sflc/src/sflc_types.h
+++ b/dm-sflc/src/sflc_types.h
@@ -103,7 +103,7 @@ struct sflc_device_base
 struct sflc_volume_base
 {
 	/* Backing device */
-	struct sflc_device	*sdev;
+	struct sflc_device	*sd_base;
 	/* Volume name: sflc_<devID>_<volIdx> */
 	char			name[32];
 

From 4db71b05a55968420bfcb700f92242325e4b3eb3 Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Fri, 27 Sep 2024 21:36:52 +0200
Subject: [PATCH 04/12] Adapt sysfs

---
 dm-sflc/src/sflc_types.h |  2 +-
 dm-sflc/src/sysfs.c      | 72 +++++++++++++++++++++-------------------
 2 files changed, 38 insertions(+), 36 deletions(-)

diff --git a/dm-sflc/src/sflc_types.h b/dm-sflc/src/sflc_types.h
index e866013..2397418 100644
--- a/dm-sflc/src/sflc_types.h
+++ b/dm-sflc/src/sflc_types.h
@@ -103,7 +103,7 @@ struct sflc_device_base
 struct sflc_volume_base
 {
 	/* Backing device */
-	struct sflc_device	*sd_base;
+	struct sflc_device_base	*sd_base;
 	/* Volume name: sflc_<devID>_<volIdx> */
 	char			name[32];
 
diff --git a/dm-sflc/src/sysfs.c b/dm-sflc/src/sysfs.c
index 2ef402d..9782ca8 100644
--- a/dm-sflc/src/sysfs.c
+++ b/dm-sflc/src/sysfs.c
@@ -87,16 +87,16 @@ void sflc_sysfs_exit()
 
 static ssize_t dev_id_show(struct kobject *kobj, struct kobj_attribute *kattr, char *buf)
 {
-	struct sflc_device *sdev = container_of(kobj, struct sflc_device, kobj);
+	struct sflc_device_base *sd_base = container_of(kobj, struct sflc_device_base, kobj);
 
-	return sysfs_emit(buf, "%u\n", sdev->dev_id);
+	return sysfs_emit(buf, "%u\n", sd_base->dev_id);
 }
 
 static ssize_t volumes_show(struct kobject *kobj, struct kobj_attribute *kattr, char *buf)
 {
-	struct sflc_device *sdev = container_of(kobj, struct sflc_device, kobj);
+	struct sflc_device_base *sd_base = container_of(kobj, struct sflc_device_base, kobj);
 
-	return sysfs_emit(buf, "%u\n", sdev->nr_volumes);
+	return sysfs_emit(buf, "%u\n", sd_base->nr_volumes);
 }
 
 
@@ -109,47 +109,47 @@ static struct attribute *sflc_device_default_attrs[] = {
 };
 ATTRIBUTE_GROUPS(sflc_device_default);
 
-static void sflc_device_kobj_release(struct kobject *kobj)
+static void sflc_device_base_kobj_release(struct kobject *kobj)
 {
-	struct sflc_device *sdev = container_of(kobj, struct sflc_device, kobj);
-	complete(&sdev->kobj_released);
+	struct sflc_device_base *sd_base = container_of(kobj, struct sflc_device_base, kobj);
+	complete(&sd_base->kobj_released);
 }
 
-static struct kobj_type sflc_device_ktype = {
-	.release = sflc_device_kobj_release,
+static struct kobj_type sflc_device_base_ktype = {
+	.release = sflc_device_base_kobj_release,
 	.sysfs_ops = &kobj_sysfs_ops,
 	.default_groups = sflc_device_default_groups
 };
 
-int sflc_sysfs_register_device(struct sflc_device *sdev)
+int sflc_sysfs_register_device_base(struct sflc_device_base *sd_base)
 {
 	int err;
 
 	/* Completion */
-	init_completion(&sdev->kobj_released);
+	init_completion(&sd_base->kobj_released);
 
 	/* Register directory <MAJOR>:<MINOR>/ under bdevs/ */
-	sdev->kobj.kset = bdevs_kset;
-	err = kobject_init_and_add(&sdev->kobj, &sflc_device_ktype, NULL,
-			"%s", sdev->name);
+	sd_base->kobj.kset = bdevs_kset;
+	err = kobject_init_and_add(&sd_base->kobj, &sflc_device_base_ktype, NULL,
+				   "%s", sd_base->name);
 	if (err)
 		goto bad;
 	/* Emit uevent */
-	kobject_uevent(&sdev->kobj, KOBJ_ADD);
+	kobject_uevent(&sd_base->kobj, KOBJ_ADD);
 
 	return 0;
 
 
 bad:
-	kobject_put(&sdev->kobj);
-	wait_for_completion(&sdev->kobj_released);
+	kobject_put(&sd_base->kobj);
+	wait_for_completion(&sd_base->kobj_released);
 	return err;
 }
 
-void sflc_sysfs_unregister_device(struct sflc_device *sdev)
+void sflc_sysfs_unregister_device_base(struct sflc_device_base *sd_base)
 {
-	kobject_put(&sdev->kobj);
-	wait_for_completion(&sdev->kobj_released);
+	kobject_put(&sd_base->kobj);
+	wait_for_completion(&sd_base->kobj_released);
 }
 
 
@@ -159,45 +159,47 @@ void sflc_sysfs_unregister_device(struct sflc_device *sdev)
  *----------------------------
  */
 
-static void sflc_volume_kobj_release(struct kobject *kobj)
+static void sflc_volume_base_kobj_release(struct kobject *kobj)
 {
-	struct sflc_volume *svol = container_of(kobj, struct sflc_volume, kobj);
+	struct sflc_volume_base *sv_base = container_of(kobj, struct sflc_volume_base, kobj);
 
-	complete(&svol->kobj_released);
+	complete(&sv_base->kobj_released);
 }
 
-static struct kobj_type sflc_volume_ktype = {
-	.release = sflc_volume_kobj_release,
+static struct kobj_type sflc_volume_base_ktype = {
+	.release = sflc_volume_base_kobj_release,
 	.sysfs_ops = &kobj_sysfs_ops,
 };
 
-int sflc_sysfs_register_volume(struct sflc_volume *svol)
+int sflc_sysfs_register_volume_base(struct sflc_volume_base *sv_base)
 {
 	int err;
 
 	/* Completion */
-	init_completion(&svol->kobj_released);
+	init_completion(&sv_base->kobj_released);
 
 	/* Register directory <svol->name>/ under device directory */
-	err = kobject_init_and_add(&svol->kobj, &sflc_volume_ktype, &svol->sdev->kobj,
-			"%s", svol->name);
+	err = kobject_init_and_add(&sv_base->kobj, &sflc_volume_base_ktype,
+				   &sv_base->sd_base->kobj,
+				   "%s", sv_base->name);
 	if (err)
 		goto bad;
 
 	/* Emit uevent */
-	kobject_uevent(&svol->kobj, KOBJ_ADD);
+	kobject_uevent(&sv_base->kobj, KOBJ_ADD);
 
 	return 0;
 
 
 bad:
-	kobject_put(&svol->kobj);
-	wait_for_completion(&svol->kobj_released);
+	kobject_put(&sv_base->kobj);
+	wait_for_completion(&sv_base->kobj_released);
 	return err;
 }
 
-void sflc_sysfs_unregister_volume(struct sflc_volume *svol)
+void sflc_sysfs_unregister_volume_base(struct sflc_volume_base *sv_base)
 {
-	kobject_put(&svol->kobj);
-	wait_for_completion(&svol->kobj_released);
+	kobject_put(&sv_base->kobj);
+	wait_for_completion(&sv_base->kobj_released);
 }
+

From b2483c12d54e3aa6f9257d5478a31ed07b513892 Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Fri, 27 Sep 2024 21:49:17 +0200
Subject: [PATCH 05/12] Add vol_idx to volume base

---
 dm-sflc/src/dev_vol.c    | 3 +--
 dm-sflc/src/sflc_types.h | 3 +++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/dm-sflc/src/dev_vol.c b/dm-sflc/src/dev_vol.c
index 2fc94b3..5bc3473 100644
--- a/dm-sflc/src/dev_vol.c
+++ b/dm-sflc/src/dev_vol.c
@@ -36,8 +36,6 @@ int sflc_dev_base_init(struct sflc_device_base *sd_base, struct dm_target *ti,
 	int err;
 
 	/* Parse arguments */
-	if (sscanf(argv[0], "%d", &mode) != 1)
-		return -EINVAL;
 	sscanf(argv[1], "%u", &dev_id);
 	err = lookup_bdev(argv[2], &devt);
 	if (err)
@@ -75,6 +73,7 @@ int sflc_vol_base_init(struct sflc_volume_base *sv_base,
 	sscanf(argv[3], "%u", &vol_idx);
 
 	/* Assign fields */
+	sv_base->vol_idx = vol_idx;
 	sprintf(sv_base->name, "sflc_%u_%u", sd_base->dev_id, vol_idx);
 	sv_base->sd_base = sd_base;
 	/* Field `ops` will be set by the derived constructor */
diff --git a/dm-sflc/src/sflc_types.h b/dm-sflc/src/sflc_types.h
index 2397418..2415229 100644
--- a/dm-sflc/src/sflc_types.h
+++ b/dm-sflc/src/sflc_types.h
@@ -104,6 +104,9 @@ struct sflc_volume_base
 {
 	/* Backing device */
 	struct sflc_device_base	*sd_base;
+
+	/* Volume index within the device */
+	u32			vol_idx;
 	/* Volume name: sflc_<devID>_<volIdx> */
 	char			name[32];
 

From 7cc60dbb5a20e1514d2eaacb570147372536a0f3 Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Mon, 30 Sep 2024 00:04:51 +0200
Subject: [PATCH 06/12] Adapt half of sflc_lite

---
 dm-sflc/src/lite/device.c    | 36 +++++++++++++++++-------------------
 dm-sflc/src/lite/sflc_lite.h | 35 ++++++++++++++---------------------
 dm-sflc/src/lite/sysfs.c     |  8 ++++----
 dm-sflc/src/lite/volume.c    | 31 +++++++++++++++++--------------
 4 files changed, 52 insertions(+), 58 deletions(-)

diff --git a/dm-sflc/src/lite/device.c b/dm-sflc/src/lite/device.c
index e62aa54..02c6e76 100644
--- a/dm-sflc/src/lite/device.c
+++ b/dm-sflc/src/lite/device.c
@@ -55,11 +55,9 @@ static void fisheryates_u32(u32 *v, u32 len)
  * 	argv[4]: number of 1 MB slices in the underlying device
  *	argv[5]: 64-byte encryption key (hex-encoded)
  */
-struct sflite_device *sflite_dev_create(struct dm_target *ti, int argc, char **argv, struct kobject *kobj)
+struct sflc_device_base *sflite_dev_ctr(struct dm_target *ti, int argc, char **argv)
 {
 	struct sflite_device *sdev;
-	dev_t devt;
-	u32 dev_id;
 	u32 tot_slices;
 	int i;
 	int err;
@@ -70,29 +68,25 @@ struct sflite_device *sflite_dev_create(struct dm_target *ti, int argc, char **a
 		return ERR_PTR(-ENOMEM);
 	}
 
+	/* Init base part */
+	err = sflc_dev_base_init(&sdev->sd_base, ti, argc, argv);
+	if (err)
+		goto bad_base;
+	sdev->sd_base.mode = SFLC_MODE_LITE;
+	sdev->sd_base.ops = &sflc_lite_ops;
+
 	/* Parse args */
 	if (argc != 6) {
-		pr_err("Wrong argument count");
+		DMERR("Wrong argument count");
 		err = -EINVAL;
 		goto bad_parse;
 	}
-	sscanf(argv[1], "%u", &dev_id);
 	if (sscanf(argv[4], "%u", &tot_slices) != 1) {
-		pr_err("Could not decode tot_slices\n");
+		DMERR("Could not decode tot_slices");
 		err = -EINVAL;
 		goto bad_parse;
 	}
 
-	sdev->dev_id = dev_id;
-
-	/* Look up block device and set name */
-	err = lookup_bdev(argv[2], &devt);
-	if (err) {
-		DMERR("Could not look up block device");
-		goto bad_lookup;
-	}
-	format_dev_t(sdev->name, devt);
-
 	/* Compute sizes */
 	sdev->tot_slices = tot_slices;
 	sdev->nr_free_slices = tot_slices;
@@ -160,12 +154,11 @@ struct sflite_device *sflite_dev_create(struct dm_target *ti, int argc, char **a
 	}
 
 	/* Add to sysfs, once initialised */
-	sdev->kobj_parent = kobj;
 	err = sflite_sysfs_add_device(sdev);
 	if (err)
 		goto bad_sysfs;
 
-	return sdev;
+	return &sdev->sd_base;
 
 
 bad_sysfs:
@@ -183,13 +176,17 @@ bad_prmslices:
 bad_ofld:
 bad_lookup:
 bad_parse:
+	sflc_dev_base_exit(&sdev->sd_base);
+bad_base:
 	kfree(sdev);
 	return ERR_PTR(err);
 }
 
 
-void sflite_dev_destroy(struct sflite_device *sdev)
+void sflite_dev_dtr(struct sflc_device_base *sd_base)
 {
+	struct sflite_device *sdev = container_of(sd_base, struct sflite_device, sd_base);
+
 	sflite_sysfs_remove_device(sdev);
 	destroy_workqueue(sdev->crypt_queue);
 	destroy_workqueue(sdev->io_queue);
@@ -197,6 +194,7 @@ void sflite_dev_destroy(struct sflite_device *sdev)
 	bioset_exit(&sdev->bioset);
 	vfree(sdev->prmslices);
 	vfree(sdev->slices_ofld);
+	sflc_dev_base_exit(&sdev->sd_base);
 	kfree(sdev);
 
 	return;
diff --git a/dm-sflc/src/lite/sflc_lite.h b/dm-sflc/src/lite/sflc_lite.h
index 1c2e5a7..f07c315 100644
--- a/dm-sflc/src/lite/sflc_lite.h
+++ b/dm-sflc/src/lite/sflc_lite.h
@@ -29,6 +29,7 @@
 #include <linux/sysfs.h>
 #include <crypto/skcipher.h>
 #include "sflite_constants.h"
+#include "sflc_types.h"
 #include "sflc_constants.h"
 
 
@@ -40,10 +41,8 @@
 
 struct sflite_device
 {
-	/* Shufflecake-unique device ID */
-	u32			dev_id;
-	/* <MAJOR>:<MINOR> */
-	char			name[16];
+	/* Base device object */
+	struct sflc_device_base	sd_base;
 
 	/* Logical size of each volume */
 	u32			tot_slices;
@@ -58,9 +57,6 @@ struct sflite_device
 	bool			*slices_ofld;
 	u32			nr_free_slices;
 
-	/* Parent sysfs directory */
-	struct kobject		*kobj_parent;
-
 	/* Resource sharing */
 	struct bio_set		bioset;
 	struct dm_io_client	*io_client;
@@ -70,6 +66,9 @@ struct sflite_device
 
 struct sflite_volume
 {
+	/* Base volume object */
+	struct sflc_volume_base	sv_base;
+
 	/* Backing device */
 	struct sflite_device	*sdev;
 
@@ -78,24 +77,17 @@ struct sflite_volume
 	struct dm_dev		*dm_dev;
 	struct dm_target	*ti;
 
-	/* Volume index within the device */
-	u32			vol_idx;
-	/* Volume name: sflite_<devID>_<volIdx> */
-	char			name[32];
-
 	/* Position map */
 	struct mutex		posmap_lock;
 	u32			*posmap;
 	u32			nr_mapped_slices;
 
-	/* Parent sysfs directory */
-	struct kobject		*kobj_parent;
-
 	/* Crypto */
 	u8			enckey[SFLITE_XTS_KEYLEN];
 	struct crypto_skcipher	*tfm;
 };
 
+/* Per-bio data */
 struct sflite_io
 {
 	struct sflite_volume	*svol;
@@ -136,7 +128,7 @@ struct sflite_io
  *----------------------------
  */
 
-extern struct target_type sflite_target_type;
+extern struct sflc_mode_ops sflc_lite_ops;
 
 
 /*
@@ -150,13 +142,14 @@ int sflite_init(void);
 void sflite_exit(void);
 
 /* Device */
-struct sflite_device *sflite_dev_create(struct dm_target *ti, int argc, char **argv, struct kobject *kobj);
-void sflite_dev_destroy(struct sflite_device *sdev);
+struct sflc_device_base *sflite_dev_ctr(struct dm_target *ti, int argc, char **argv);
+void sflite_dev_dtr(struct sflc_device_base *sd_base);
 
 /* Volume */
-struct sflite_volume *sflite_vol_create(struct dm_target *ti, struct sflite_device *sdev,
-		int argc, char **argv, struct kobject *kobj);
-void sflite_vol_destroy(struct sflite_volume *svol);
+struct sflc_volume_base *sflite_vol_ctr(struct sflc_device_base *sd_base,
+					struct dm_target *ti,
+					int argc, char **argv);
+void sflite_vol_dtr(struct sflc_volume_base *sv_base);
 
 /* Sysfs */
 int sflite_sysfs_add_device(struct sflite_device *sdev);
diff --git a/dm-sflc/src/lite/sysfs.c b/dm-sflc/src/lite/sysfs.c
index 88e2d06..3c6d72f 100644
--- a/dm-sflc/src/lite/sysfs.c
+++ b/dm-sflc/src/lite/sysfs.c
@@ -67,12 +67,12 @@ static const struct attribute_group sflite_device_attr_group = {
 
 int sflite_sysfs_add_device(struct sflite_device *sdev)
 {
-	return sysfs_create_group(sdev->kobj_parent, &sflite_device_attr_group);
+	return sysfs_create_group(&sdev->sd_base.kobj, &sflite_device_attr_group);
 }
 
 void sflite_sysfs_remove_device(struct sflite_device *sdev)
 {
-	sysfs_remove_group(sdev->kobj_parent, &sflite_device_attr_group);
+	sysfs_remove_group(&sdev->sd_base.kobj, &sflite_device_attr_group);
 }
 
 
@@ -107,10 +107,10 @@ static const struct attribute_group sflite_volume_attr_group = {
 
 int sflite_sysfs_add_volume(struct sflite_volume *svol)
 {
-	return sysfs_create_group(svol->kobj_parent, &sflite_volume_attr_group);
+	return sysfs_create_group(&svol->sv_base.kobj, &sflite_volume_attr_group);
 }
 
 void sflite_sysfs_remove_volume(struct sflite_volume *svol)
 {
-	sysfs_remove_group(svol->kobj_parent, &sflite_volume_attr_group);
+	sysfs_remove_group(&svol->sv_base.kobj, &sflite_volume_attr_group);
 }
diff --git a/dm-sflc/src/lite/volume.c b/dm-sflc/src/lite/volume.c
index e37d9c1..a8f5933 100644
--- a/dm-sflc/src/lite/volume.c
+++ b/dm-sflc/src/lite/volume.c
@@ -34,11 +34,12 @@
  * 	argv[4]: number of 1 MB slices in the underlying device
  *	argv[5]: 64-byte encryption key (hex-encoded)
  */
-struct sflite_volume *sflite_vol_create(struct dm_target *ti, struct sflite_device* sdev,
-		int argc, char **argv, struct kobject *kobj)
+struct sflc_volume_base *sflite_vol_ctr(struct sflc_device_base *sd_base,
+					struct dm_target *ti,
+					int argc, char **argv)
 {
 	struct sflite_volume *svol;
-	u32 vol_idx;
+	struct sflite_device *sdev = container_of(sd_base, struct sflite_device, sd_base);
 	int err;
 
 	svol = kzalloc(sizeof(*svol), GFP_KERNEL);
@@ -47,17 +48,17 @@ struct sflite_volume *sflite_vol_create(struct dm_target *ti, struct sflite_devi
 		return ERR_PTR(-ENOMEM);
 	}
 
+	/* Init base part */
+	err = sflc_vol_base_init(&svol->sv_base, sd_base, ti, argc, argv);
+	if (err)
+		goto bad_base;
+
 	/* Parse arguments */
 	if (argc != 6) {
 		DMERR("Wrong argument count");
 		err = -EINVAL;
 		goto bad_parse;
 	}
-	if (sscanf(argv[3], "%u", &vol_idx) != 1) {
-		DMERR("Could not decode tot_slices\n");
-		err = -EINVAL;
-		goto bad_parse;
-	}
 	/* Decode the encryption key */
 	if (strlen(argv[5]) != 2 * SFLITE_XTS_KEYLEN) {
 		DMERR("Invalid key length");
@@ -72,11 +73,9 @@ struct sflite_volume *sflite_vol_create(struct dm_target *ti, struct sflite_devi
 	}
 
 	svol->sdev = sdev;
-	svol->vol_idx = vol_idx;
-	sprintf(svol->name, "sflc_%u_%u", sdev->dev_id, vol_idx);
 
 	svol->ti = ti;
-	err = dm_get_device(ti, sdev->name,
+	err = dm_get_device(ti, sdev->sd_base.name,
 			dm_table_get_mode(ti->table), &svol->dm_dev);
 	if (err) {
 		ti->error = "Device lookup failed";
@@ -114,7 +113,6 @@ struct sflite_volume *sflite_vol_create(struct dm_target *ti, struct sflite_devi
 	}
 
 	/* Add to sysfs, once initialised */
-	svol->kobj_parent = kobj;
 	err = sflite_sysfs_add_volume(svol);
 	if (err) {
 		DMERR("Could not register volume with sysfs; error %d", err);
@@ -133,7 +131,7 @@ struct sflite_volume *sflite_vol_create(struct dm_target *ti, struct sflite_devi
 	ti->per_io_data_size = sizeof(struct sflite_io);
 	ti->private = svol;
 
-	return svol;
+	return &svol->sv_base;
 
 
 bad_sysfs:
@@ -146,17 +144,22 @@ bad_tfm_alloc:
 	dm_put_device(ti, svol->dm_dev);
 bad_dm_dev:
 bad_parse:
+	sflc_vol_base_exit(&svol->sv_base);
+bad_base:
 	kfree(svol);
 	return ERR_PTR(err);
 }
 
 
-void sflite_vol_destroy(struct sflite_volume *svol)
+void sflite_vol_dtr(struct sflc_volume_base *sv_base)
 {
+	struct sflite_volume *svol = container_of(sv_base, struct sflite_volume, sv_base);
+
 	sflite_sysfs_remove_volume(svol);
 	vfree(svol->posmap);
 	crypto_free_skcipher(svol->tfm);
 	dm_put_device(svol->ti, svol->dm_dev);
+	sflc_vol_base_exit(&svol->sv_base);
 	kfree(svol);
 
 	return;

From d920eedb13210d91f56efb503115ab3dc7be4eca Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Mon, 30 Sep 2024 22:20:28 +0200
Subject: [PATCH 07/12] Adapt sflc_lite

---
 dm-sflc/src/lite/device.c    |  4 ++--
 dm-sflc/src/lite/posmap.c    |  2 +-
 dm-sflc/src/lite/sflc_lite.c | 14 +++++++++-----
 dm-sflc/src/lite/sflc_lite.h |  2 +-
 dm-sflc/src/lite/volume.c    |  1 +
 5 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/dm-sflc/src/lite/device.c b/dm-sflc/src/lite/device.c
index 02c6e76..55ff28e 100644
--- a/dm-sflc/src/lite/device.c
+++ b/dm-sflc/src/lite/device.c
@@ -137,7 +137,7 @@ struct sflc_device_base *sflite_dev_ctr(struct dm_target *ti, int argc, char **a
 	/* I/O workqueue */
 	sdev->io_queue = alloc_workqueue("sflite_%s_io",
 			WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
-			0, sdev->name);
+			0, sdev->sd_base.name);
 	if (!sdev->io_queue) {
 		err = -ENOMEM;
 		DMERR("Could not allocate I/O workqueue");
@@ -146,7 +146,7 @@ struct sflc_device_base *sflite_dev_ctr(struct dm_target *ti, int argc, char **a
 	/* Decryption workqueue */
 	sdev->crypt_queue = alloc_workqueue("sflite_%s_crypt",
 			WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
-			0, sdev->name);
+			0, sdev->sd_base.name);
 	if (!sdev->crypt_queue) {
 		err = -ENOMEM;
 		DMERR("Could not allocate decryption workqueue");
diff --git a/dm-sflc/src/lite/posmap.c b/dm-sflc/src/lite/posmap.c
index 3ee2551..8a2e412 100644
--- a/dm-sflc/src/lite/posmap.c
+++ b/dm-sflc/src/lite/posmap.c
@@ -311,7 +311,7 @@ static int _deserialise_and_sanitise_posmap(struct sflite_volume *svol)
 		/* If PSI already taken, sample a new one */
 		if (sdev->slices_ofld[psi]) {
 			DMWARN("Corruption of volume %u: LSI %u was evicted from PSI %u",
-					svol->vol_idx, lsi, psi);
+					svol->sv_base.vol_idx, lsi, psi);
 			err = peek_next_free_psi(sdev, &psi);
 			if (err)
 				return err;
diff --git a/dm-sflc/src/lite/sflc_lite.c b/dm-sflc/src/lite/sflc_lite.c
index edc245f..f17adf7 100644
--- a/dm-sflc/src/lite/sflc_lite.c
+++ b/dm-sflc/src/lite/sflc_lite.c
@@ -41,9 +41,9 @@
 
 static int sflite_map(struct dm_target *ti, struct bio *bio)
 {
+	struct sflc_volume_base *sv_base = ti->private;
+	struct sflite_volume *svol = container_of(sv_base, struct sflite_volume, sv_base);
 	struct sflite_io *sio = dm_per_bio_data(bio, sizeof(struct sflite_io));
-	struct sflc_volume *top_vol = ti->private;
-	struct sflite_volume *svol = top_vol->sflite_vol;
 	sector_t lblk_num = bio->bi_iter.bi_sector >> SFLITE_BLOCK_SHIFT;
 
 	if (unlikely(!bio_has_data(bio))) {
@@ -116,8 +116,8 @@ static void sflite_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 static int sflite_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
 {
-	struct sflc_volume *top_vol = ti->private;
-	struct sflite_volume *svol = top_vol->sflite_vol;
+	struct sflc_volume_base *sv_base = ti->private;
+	struct sflite_volume *svol = container_of(sv_base, struct sflite_volume, sv_base);
 	struct sflite_device *sdev = svol->sdev;
 
 	if (!fn) {
@@ -129,7 +129,11 @@ static int sflite_iterate_devices(struct dm_target *ti, iterate_devices_callout_
 }
 
 
-struct target_type sflite_target_type = {
+struct sflc_mode_ops sflc_lite_ops = {
+	.dev_ctr		= sflite_dev_ctr,
+	.dev_dtr		= sflite_dev_dtr,
+	.vol_ctr		= sflite_vol_ctr,
+	.vol_dtr		= sflite_vol_dtr,
 	.map			= sflite_map,
 	.io_hints		= sflite_io_hints,
 	.iterate_devices	= sflite_iterate_devices,
diff --git a/dm-sflc/src/lite/sflc_lite.h b/dm-sflc/src/lite/sflc_lite.h
index f07c315..59becb7 100644
--- a/dm-sflc/src/lite/sflc_lite.h
+++ b/dm-sflc/src/lite/sflc_lite.h
@@ -111,7 +111,7 @@ struct sflite_io
 /* Starting sector of position map */
 #define SFLITE_POSMAP_START_SECTOR(svol) \
 	(SFLITE_BLOCK_SCALE * (1 + SFLITE_DEV_MAX_VOLUMES) + \
-	(svol)->vol_idx * (svol)->sdev->posmap_size_sectors)
+	(svol)->sv_base.vol_idx * (svol)->sdev->posmap_size_sectors)
 
 
 /* Physical sector of a remapped bio */
diff --git a/dm-sflc/src/lite/volume.c b/dm-sflc/src/lite/volume.c
index a8f5933..3df5edd 100644
--- a/dm-sflc/src/lite/volume.c
+++ b/dm-sflc/src/lite/volume.c
@@ -52,6 +52,7 @@ struct sflc_volume_base *sflite_vol_ctr(struct sflc_device_base *sd_base,
 	err = sflc_vol_base_init(&svol->sv_base, sd_base, ti, argc, argv);
 	if (err)
 		goto bad_base;
+	svol->sv_base.ops = &sflc_lite_ops;
 
 	/* Parse arguments */
 	if (argc != 6) {

From bb92f256e778199b177b1127f08d1b0ae205feab Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Mon, 30 Sep 2024 23:54:07 +0200
Subject: [PATCH 08/12] Adapt sflc_legacy

---
 dm-sflc/src/legacy/device/device.c | 50 ++++++++++++------------------
 dm-sflc/src/legacy/device/device.h | 25 ++++-----------
 dm-sflc/src/legacy/sflc_legacy.h   |  2 +-
 dm-sflc/src/legacy/sysfs.c         | 29 ++++++-----------
 dm-sflc/src/legacy/target.c        | 26 +++++++---------
 dm-sflc/src/legacy/volume/volume.c | 37 +++++++++++-----------
 dm-sflc/src/legacy/volume/volume.h | 18 +++++------
 7 files changed, 75 insertions(+), 112 deletions(-)

diff --git a/dm-sflc/src/legacy/device/device.c b/dm-sflc/src/legacy/device/device.c
index 1725d65..e510c40 100644
--- a/dm-sflc/src/legacy/device/device.c
+++ b/dm-sflc/src/legacy/device/device.c
@@ -63,11 +63,10 @@ static int sflegc_dev_initAndShufflePsiArray(u32 *psi_array, u32 len);
  * 	argv[4]: number of 1 MB slices in the underlying device
  *	argv[5]: 32-byte encryption key (hex-encoded)
  */
-sflegc_Device *sflegc_dev_create(struct dm_target *ti, int argc, char **argv, struct kobject *kobj)
+struct sflc_device_base *sflegc_dev_ctr(struct dm_target *ti, int argc, char **argv)
 {
 	sflegc_Device * dev;
 	u32 tot_slices;
-	u32 dev_id;
 	int err;
 	int i;
 
@@ -79,25 +78,25 @@ sflegc_Device *sflegc_dev_create(struct dm_target *ti, int argc, char **argv, st
 		goto err_alloc_dev;
 	}
 
+	/* Init base part */
+	err = sflc_dev_base_init(&dev->sd_base, ti, argc, argv);
+	if (err)
+		goto bad_base;
+	dev->sd_base.mode = SFLC_MODE_LEGACY;
+	dev->sd_base.ops = &sflc_legacy_ops;
+
 	/* Parse args */
 	if (argc != 6) {
 		pr_err("Wrong argument count");
 		err = -EINVAL;
 		goto err_parse;
 	}
-	sscanf(argv[1], "%u", &dev_id);
 	if (sscanf(argv[4], "%u", &tot_slices) != 1) {
 		pr_err("Could not decode tot_slices\n");
 		err = -EINVAL;
 		goto err_parse;
 	}
 
-	/* Init list node here, so it's always safe to list_del() */
-	INIT_LIST_HEAD(&dev->list_node);
-
-	/* Set device ID */
-	dev->dev_id = dev_id;
-
 	/* Set backing real device */
 	err = dm_get_device(ti, argv[2], dm_table_get_mode(ti->table), &dev->bdev);
 	if (err) {
@@ -105,14 +104,6 @@ sflegc_Device *sflegc_dev_create(struct dm_target *ti, int argc, char **argv, st
 		goto err_dm_get_dev;
 	}
 	dev->ti = ti;
-	/* And its path */
-	dev->bdev_path = kmalloc(strlen(argv[2]) + 1, GFP_KERNEL);
-	if (!dev->bdev_path) {
-		pr_err("Could not allocate %lu bytes for dev->real_dev_path\n", strlen(argv[2]) + 1);
-		err = -ENOMEM;
-		goto err_alloc_real_dev_path;
-	}
-	strcpy(dev->bdev_path, argv[2]);
 
 	/* Init volumes */
 	for (i = 0; i < SFLEGC_DEV_MAX_VOLUMES; ++i) {
@@ -173,14 +164,13 @@ sflegc_Device *sflegc_dev_create(struct dm_target *ti, int argc, char **argv, st
 	INIT_LIST_HEAD(&dev->iv_lru_list);
 
 	/* Add to sysfs */
-	dev->kobj_parent = kobj;
 	err = sflegc_sysfs_add_device(dev);
 	if (err) {
 		pr_err("Could not add device to sysfs; error %d\n", err);
 		goto err_sysfs;
 	}
 
-	return dev;
+	return &dev->sd_base;
 
 
 err_sysfs:
@@ -191,35 +181,33 @@ err_initshuffle_psi_array:
 err_alloc_psi_array:
 	vfree(dev->rmap);
 err_alloc_rmap:
-	kfree(dev->bdev_path);
-err_alloc_real_dev_path:
 	dm_put_device(ti, dev->bdev);
 err_dm_get_dev:
 err_parse:
+	sflc_dev_base_exit(&dev->sd_base);
+bad_base:
 	kfree(dev);
 err_alloc_dev:
 	return ERR_PTR(err);
 }
 
 
-/* Returns false if still busy (not all volumes have been removed). Frees the Device. */
-bool sflegc_dev_destroy(sflegc_Device * dev)
+void sflite_dev_dtr(struct sflc_device_base *sd_base)
 {
+	struct sflegc_device *dev = container_of(sd_base, sflegc_Device, sd_base);
+
 	/* Check if we actually have to put this device */
 	if (!dev) {
-		return false;
+		return;
 	}
 	if (dev->vol_cnt > 0) {
 		pr_warn("Called while still holding %d volumes\n", dev->vol_cnt);
-		return false;
+		return;
 	}
 
 	/* Flush all IVs */
 	sflegc_dev_flushIvs(dev);
 
-	/* List */
-	list_del(&dev->list_node);
-
 	/* Sysfs */
 	sflegc_sysfs_remove_device(dev);
 
@@ -234,12 +222,14 @@ bool sflegc_dev_destroy(sflegc_Device * dev)
 
 	/* Backing device */
 	dm_put_device(dev->ti, dev->bdev);
-	kfree(dev->bdev_path);
+
+	/* Base part */
+	sflc_dev_base_exit(&dev->sd_base);
 
 	/* Free the device itself */
 	kfree(dev);
 
-	return true;
+	return;
 }
 
 
diff --git a/dm-sflc/src/legacy/device/device.h b/dm-sflc/src/legacy/device/device.h
index a6109e7..63430d6 100644
--- a/dm-sflc/src/legacy/device/device.h
+++ b/dm-sflc/src/legacy/device/device.h
@@ -50,6 +50,7 @@ typedef struct sflegc_dev_iv_cache_entry_s sflegc_dev_IvCacheEntry;
 
 #include <linux/device-mapper.h>
 
+#include "sflc_types.h"
 #include "legacy/sflc_legacy.h"
 #include "legacy/volume/volume.h"
 #include "legacy/crypto/symkey/symkey.h"
@@ -101,13 +102,13 @@ struct sflegc_dev_iv_cache_entry_s
 
 struct sflegc_device_s
 {
+	/* Base device object */
+	struct sflc_device_base		sd_base;
+
 	/* Underlying block device */
 	struct dm_dev                 * bdev;
-	char                          * bdev_path;
 	/* Target instance that owns the bdev reference */
 	struct dm_target		*ti;
-	/* Shufflecake-unique numeric ID of this device */
-	u32				dev_id;
 
 	/* All volumes linked to this device */
 	sflegc_Volume                    * vol[SFLEGC_DEV_MAX_VOLUMES];
@@ -130,18 +131,12 @@ struct sflegc_device_s
 	u32				vol_header_size;
 	u32				dev_header_size;
 
-	/* Parent sysfs directory */
-	struct kobject			*kobj_parent;
-
 	/* LRU cache of IV blocks */
 	struct mutex			iv_cache_lock;
 	wait_queue_head_t		iv_cache_waitqueue;
 	sflegc_dev_IvCacheEntry	     ** iv_cache;
 	u32				iv_cache_nr_entries;
 	struct list_head		iv_lru_list;
-
-	/* We keep all devices in a list */
-	struct list_head                list_node;  
 };
 
 
@@ -149,17 +144,9 @@ struct sflegc_device_s
  *            PUBLIC FUNCTIONS PROTOTYPES            *
  *****************************************************/
 
-/*
- * None of these functions acquire the big device lock: it must be held
- * by the caller.
- */
-
-/* Creates Device and adds it to the list. Returns an ERR_PTR() if unsuccessful. */
-sflegc_Device * sflegc_dev_create(struct dm_target *ti, int argc, char **argv, struct kobject *kobj);
-
-/* Returns false if still busy (not all volumes have been removed) Frees the Device. */
-bool sflegc_dev_destroy(sflegc_Device * dev);
 
+struct sflc_device_base *sflegc_dev_ctr(struct dm_target *ti, int argc, char **argv);
+void sflegc_dev_dtr(struct sflc_device_base *sd_base);
 
 /* Returns false if volume index was already occupied. */
 bool sflegc_dev_addVolume(sflegc_Device * dev, sflegc_Volume * vol, int vol_idx);
diff --git a/dm-sflc/src/legacy/sflc_legacy.h b/dm-sflc/src/legacy/sflc_legacy.h
index 70f0a95..2a3824f 100644
--- a/dm-sflc/src/legacy/sflc_legacy.h
+++ b/dm-sflc/src/legacy/sflc_legacy.h
@@ -31,7 +31,7 @@
 #include "legacy/volume/volume.h"
 
 
-extern struct target_type sflegc_target_type;
+extern struct sflc_mode_ops sflc_legacy_ops;
 
 
 int sflegc_init(void);
diff --git a/dm-sflc/src/legacy/sysfs.c b/dm-sflc/src/legacy/sysfs.c
index df6615e..626f93d 100644
--- a/dm-sflc/src/legacy/sysfs.c
+++ b/dm-sflc/src/legacy/sysfs.c
@@ -43,13 +43,10 @@
 /* Show the total number of slices in a device */
 static ssize_t tot_slices_show(struct kobject *kobj, struct kobj_attribute *kattr, char *buf)
 {
-	struct sflc_device *top_dev;
-	sflegc_Device * dev;
+	struct sflc_device_base *sd_base = container_of(kobj, struct sflc_device_base, kobj);
+	sflegc_Device * dev = container_of(sd_base, sflegc_Device, sd_base);
 	ssize_t ret;
 
-	top_dev = container_of(kobj, struct sflc_device, kobj);
-	dev = top_dev->sflegc_dev;
-
 	/* Write the tot_slices */
 	ret = sysfs_emit(buf, "%u\n", dev->tot_slices);
 
@@ -59,13 +56,10 @@ static ssize_t tot_slices_show(struct kobject *kobj, struct kobj_attribute *katt
 /* Show the number of free slices in a device */
 static ssize_t free_slices_show(struct kobject *kobj, struct kobj_attribute *kattr, char *buf)
 {
-	struct sflc_device *top_dev;
-	sflegc_Device * dev;
+	struct sflc_device_base *sd_base = container_of(kobj, struct sflc_device_base, kobj);
+	sflegc_Device * dev = container_of(sd_base, sflegc_Device, sd_base);
 	ssize_t ret;
 
-	top_dev = container_of(kobj, struct sflc_device, kobj);
-	dev = top_dev->sflegc_dev;
-
 	/* Write the free_slices */
 	if (mutex_lock_interruptible(&dev->slices_lock))
 		return -ERESTARTSYS;
@@ -88,12 +82,12 @@ static const struct attribute_group sflegc_device_attr_group = {
 
 int sflegc_sysfs_add_device(sflegc_Device *dev)
 {
-	return sysfs_create_group(dev->kobj_parent, &sflegc_device_attr_group);
+	return sysfs_create_group(dev->sd_base.kobj, &sflegc_device_attr_group);
 }
 
 void sflegc_sysfs_remove_device(sflegc_Device *dev)
 {
-	sysfs_remove_group(dev->kobj_parent, &sflegc_device_attr_group);
+	sysfs_remove_group(dev->sd_base.kobj, &sflegc_device_attr_group);
 }
 
 
@@ -106,13 +100,10 @@ void sflegc_sysfs_remove_device(sflegc_Device *dev)
 /* Show the number of mapped slices in a volume */
 static ssize_t mapped_slices_show(struct kobject *kobj, struct kobj_attribute *kattr, char *buf)
 {
-	struct sflc_volume *top_vol;
-	sflegc_Volume * vol;
+	struct sflc_volume_base *sv_base = container_of(kobj, struct sflc_volume_base, kobj);
+	sflegc_Volume * vol = container_of(sv_base, sflegc_Volume, sv_base);
 	ssize_t ret;
 
-	top_vol = container_of(kobj, struct sflc_volume, kobj);
-	vol = top_vol->sflegc_vol;
-
 	/* Write the free_slices */
 	if (mutex_lock_interruptible(&vol->fmap_lock))
 		return -ERESTARTSYS;
@@ -133,10 +124,10 @@ static const struct attribute_group sflegc_volume_attr_group = {
 
 int sflegc_sysfs_add_volume(sflegc_Volume *vol)
 {
-	return sysfs_create_group(vol->kobj_parent, &sflegc_volume_attr_group);
+	return sysfs_create_group(vol->sv_base.kobj, &sflegc_volume_attr_group);
 }
 
 void sflegc_sysfs_remove_volume(sflegc_Volume *vol)
 {
-	sysfs_remove_group(vol->kobj_parent, &sflegc_volume_attr_group);
+	sysfs_remove_group(vol->sv_base.kobj, &sflegc_volume_attr_group);
 }
diff --git a/dm-sflc/src/legacy/target.c b/dm-sflc/src/legacy/target.c
index 08a0d40..a95d60d 100644
--- a/dm-sflc/src/legacy/target.c
+++ b/dm-sflc/src/legacy/target.c
@@ -55,10 +55,14 @@ static int sflegc_tgt_iterateDevices(struct dm_target *ti, iterate_devices_callo
  *           PUBLIC VARIABLES DEFINITIONS            *
  *****************************************************/
 
-struct target_type sflegc_target_type = {
-	.map                = sflegc_tgt_map,
-	.io_hints           = sflegc_tgt_ioHints,
-	.iterate_devices    = sflegc_tgt_iterateDevices,
+struct sflc_mode_ops sflc_legacy_ops = {
+	.dev_ctr		= sflegc_dev_ctr,
+	.dev_dtr		= sflegc_dev_dtr,
+	.vol_ctr		= sflegc_vol_ctr,
+	.vol_dtr		= sflegc_vol_dtr,
+	.map			= sflegc_tgt_map,
+	.io_hints		= sflegc_tgt_ioHints,
+	.iterate_devices	= sflegc_tgt_iterateDevices,
 };
 
 /*****************************************************
@@ -70,8 +74,8 @@ struct target_type sflegc_target_type = {
 static int sflegc_tgt_map(struct dm_target *ti, struct bio *bio) 
 {
 	int err;
-	struct sflc_volume *top_vol = ti->private;
-	sflegc_Volume *vol = top_vol->sflegc_vol;
+	struct sflc_volume_base *sv_base = ti->private;
+	sflegc_Volume *vol = container_of(sv_base, sflegc_Volume, sv_base);
 
         /* If no data, just quickly remap the sector and the block device (no crypto) */
 	/* TODO: this is dangerous for deniability, will need more filtering */
@@ -117,11 +121,6 @@ static int sflegc_tgt_map(struct dm_target *ti, struct bio *bio)
 /* Callback executed to inform the DM about our 4096-byte sector size */
 static void sflegc_tgt_ioHints(struct dm_target *ti, struct queue_limits *limits)
 {
-	struct sflc_volume *top_vol = ti->private;
-	sflegc_Volume *vol = top_vol->sflegc_vol;
-
-	pr_info("Called io_hints on volume \"%s\"\n", vol->vol_name);
-
 	limits->logical_block_size = SFLEGC_DEV_SECTOR_SIZE;
 	limits->physical_block_size = SFLEGC_DEV_SECTOR_SIZE;
 
@@ -135,11 +134,10 @@ static void sflegc_tgt_ioHints(struct dm_target *ti, struct queue_limits *limits
 static int sflegc_tgt_iterateDevices(struct dm_target *ti, iterate_devices_callout_fn fn,
 									void *data)
 {
-	struct sflc_volume *top_vol = ti->private;
-	sflegc_Volume *vol = top_vol->sflegc_vol;
+	struct sflc_volume_base *sv_base = ti->private;
+	sflegc_Volume *vol = container_of(sv_base, sflegc_Volume, sv_base);
 	sflegc_Device * dev = vol->dev;
 
-	pr_debug("Called iterate_devices on volume \"%s\"\n", vol->vol_name);
 
 	if (!fn) {
 		return -EINVAL;
diff --git a/dm-sflc/src/legacy/volume/volume.c b/dm-sflc/src/legacy/volume/volume.c
index e229312..8c62e1f 100644
--- a/dm-sflc/src/legacy/volume/volume.c
+++ b/dm-sflc/src/legacy/volume/volume.c
@@ -50,11 +50,12 @@
  * 	argv[4]: number of 1 MB slices in the underlying device
  *	argv[5]: 32-byte encryption key (hex-encoded)
  */
-sflegc_Volume * sflegc_vol_create(struct dm_target * ti, sflegc_Device* dev,
-		int argc, char **argv, struct kobject *kobj)
+struct sflc_volume_base *sflegc_vol_ctr(struct sflc_device_base *sd_base,
+					struct dm_target *ti,
+					int argc, char **argv)
 {
 	sflegc_Volume * vol;
-	int vol_idx;
+	sflegc_Device *dev = container_of(sd_base, sflegc_Device, sd_base);
 	u8 enckey[SFLEGC_SK_KEY_LEN];
 	int err;
 
@@ -66,17 +67,18 @@ sflegc_Volume * sflegc_vol_create(struct dm_target * ti, sflegc_Device* dev,
 		goto err_alloc_vol;
 	}
 
+	/* Init base part */
+	err = sflc_vol_base_init(&vol->sv_base, sd_base, ti, argc, argv);
+	if (err)
+		goto bad_base;
+	vol->sv_base.ops = &sflc_legacy_ops;
+
 	/* Parse args */
 	if (argc != 6) {
 		pr_err("Wrong argument count");
 		err = -EINVAL;
 		goto err_parse;
 	}
-	if (sscanf(argv[3], "%u", &vol_idx) != 1) {
-		pr_err("Could not decode tot_slices\n");
-		err = -EINVAL;
-		goto err_parse;
-	}
 	/* Decode the encryption key */
 	if (strlen(argv[5]) != 2 * SFLEGC_SK_KEY_LEN) {
 		pr_err("Hexadecimal key (length %lu): %s\n", strlen(argv[5]), argv[5]);
@@ -90,11 +92,7 @@ sflegc_Volume * sflegc_vol_create(struct dm_target * ti, sflegc_Device* dev,
 		goto err_parse;
 	}
 
-	/* Set volume name */
-	sprintf(vol->vol_name, "sflc_%u_%d", dev->dev_id, vol_idx);
-
 	/* Sysfs stuff */
-	vol->kobj_parent = kobj;
 	err = sflegc_sysfs_add_volume(vol);
 	if (err) {
 		pr_err("Could not add volume to sysfs; error %d\n", err);
@@ -102,13 +100,12 @@ sflegc_Volume * sflegc_vol_create(struct dm_target * ti, sflegc_Device* dev,
 	}
 
 	/* Backing device */
-	if (!sflegc_dev_addVolume(dev, vol, vol_idx)) {
+	if (!sflegc_dev_addVolume(dev, vol, vol->sv_base.vol_idx)) {
 		pr_err("Could not add volume to device\n");
 		err = -EINVAL;
 		goto err_add_to_dev;
 	}
 	vol->dev = dev;
-	vol->vol_idx = vol_idx;
 
 	/* Crypto */
 	vol->skctx = sflegc_sk_createContext(enckey);
@@ -152,7 +149,7 @@ sflegc_Volume * sflegc_vol_create(struct dm_target * ti, sflegc_Device* dev,
 	   TODO: will need to support them to release slice mappings */
 	ti->num_discard_bios = 0;
 
-	return vol;
+	return &vol->sv_base;
 
 
 err_load_fmap:
@@ -165,23 +162,24 @@ err_add_to_dev:
 	sflegc_sysfs_remove_volume(vol);
 err_sysfs:
 err_parse:
+	sflc_vol_base_exit(&vol->sv_base);
+bad_base:
 	kfree(vol);
 err_alloc_vol:
 	return ERR_PTR(err);
 }
 
 /* Removes the volume from the device and frees it. */
-void sflegc_vol_destroy(sflegc_Volume * vol)
+void sflite_vol_dtr(struct sflc_volume_base *sv_base)
 {
+	sflegc_Volume *vol = container_of(sv_base, sflegc_Volume, sv_base);
 	int err;
 
 	/* Store fmap */
-	pr_notice("Going to store position map of volume %s\n", vol->vol_name);
 	err = sflegc_vol_storeFmap(vol);
 	if (err) {
 		pr_err("Could not store position map; error %d\n", err);
 	}
-	pr_debug("Successfully stored position map of volume %s\n", vol->vol_name);
 	/* Free it */
 	vfree(vol->fmap);
 
@@ -194,6 +192,9 @@ void sflegc_vol_destroy(sflegc_Volume * vol)
 	/* Destroy sysfs entries */
 	sflegc_sysfs_remove_volume(vol);
 
+	/* Base part */
+	sflc_vol_base_exit(&vol->sv_base);
+
 	/* Free volume structure */
 	kfree(vol);
 
diff --git a/dm-sflc/src/legacy/volume/volume.h b/dm-sflc/src/legacy/volume/volume.h
index 3222433..c61de66 100644
--- a/dm-sflc/src/legacy/volume/volume.h
+++ b/dm-sflc/src/legacy/volume/volume.h
@@ -47,6 +47,7 @@ typedef struct sflegc_volume_s sflegc_Volume;
 
 #include <linux/blk_types.h>
 
+#include "sflc_types.h"
 #include "legacy/sflc_legacy.h"
 #include "legacy/device/device.h"
 #include "legacy/crypto/symkey/symkey.h"
@@ -103,13 +104,11 @@ struct sflegc_vol_decrypt_work_s
 
 struct sflegc_volume_s
 {
-	/* Name of the volume, sflc_<devID>_<volIdx>*/
-	char           		      	vol_name[SFLEGC_VOL_NAME_MAX_LEN + 1];
+	/* Base volume object */
+	struct sflc_volume_base		sv_base;
 
 	/* Backing device */
 	sflegc_Device    		      * dev;
-	/* Index of this volume within the device's volume array */
-	u32				vol_idx;
 
 	/* Forward position map */
 	struct mutex			fmap_lock;
@@ -117,8 +116,6 @@ struct sflegc_volume_s
 	/* Stats on the fmap */
 	u32				mapped_slices;
 
-	/* Parent sysfs directory */
-	struct kobject			*kobj_parent;
 
 	/* Crypto */
 	sflegc_sk_Context  	      *	skctx;
@@ -129,11 +126,10 @@ struct sflegc_volume_s
  *            PUBLIC FUNCTIONS PROTOTYPES            *
  *****************************************************/
 
-/* Creates volume and adds it to the device. Returns an ERR_PTR() if unsuccessful */
-sflegc_Volume * sflegc_vol_create(struct dm_target * ti, sflegc_Device* dev,
-		int argc, char **argv, struct kobject *kobj);
-/* Removes the volume from the device and frees it. */
-void sflegc_vol_destroy(sflegc_Volume * vol);
+struct sflc_volume_base *sflegc_vol_ctr(struct sflc_device_base *sd_base,
+					struct dm_target *ti,
+					int argc, char **argv);
+void sflegc_vol_dtr(struct sflc_volume_base *sv_base);
 
 /* Remaps the underlying block device and the sector number */
 int sflegc_vol_remapBioFast(sflegc_Volume * vol, struct bio * bio);

From 1df6b0774c6c5d5d92498b415a5ae05e6d1cfd08 Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Tue, 1 Oct 2024 00:33:13 +0200
Subject: [PATCH 09/12] Adapt everything: now it compiles, still to be tested

---
 dm-sflc/src/legacy/device/device.c |  5 +-
 dm-sflc/src/legacy/sysfs.c         |  8 +--
 dm-sflc/src/legacy/volume/fmap.c   |  8 +--
 dm-sflc/src/legacy/volume/volume.c |  9 ++--
 dm-sflc/src/lite/device.c          |  2 +-
 dm-sflc/src/lite/sysfs.c           | 12 ++---
 dm-sflc/src/lite/volume.c          |  1 +
 dm-sflc/src/sflc.c                 | 82 +++++++++++++++++++-----------
 dm-sflc/src/sflc.h                 |  2 +-
 dm-sflc/src/sflc_constants.h       |  1 +
 dm-sflc/src/sflc_types.h           |  2 -
 11 files changed, 76 insertions(+), 56 deletions(-)

diff --git a/dm-sflc/src/legacy/device/device.c b/dm-sflc/src/legacy/device/device.c
index e510c40..e64b613 100644
--- a/dm-sflc/src/legacy/device/device.c
+++ b/dm-sflc/src/legacy/device/device.c
@@ -33,6 +33,7 @@
 #include "legacy/device/device.h"
 #include "legacy/utils/vector.h"
 #include "legacy/log/log.h"
+#include "sflc.h"
 
 #include <linux/vmalloc.h>
 
@@ -192,9 +193,9 @@ err_alloc_dev:
 }
 
 
-void sflite_dev_dtr(struct sflc_device_base *sd_base)
+void sflegc_dev_dtr(struct sflc_device_base *sd_base)
 {
-	struct sflegc_device *dev = container_of(sd_base, sflegc_Device, sd_base);
+	sflegc_Device *dev = container_of(sd_base, sflegc_Device, sd_base);
 
 	/* Check if we actually have to put this device */
 	if (!dev) {
diff --git a/dm-sflc/src/legacy/sysfs.c b/dm-sflc/src/legacy/sysfs.c
index 626f93d..7d567ec 100644
--- a/dm-sflc/src/legacy/sysfs.c
+++ b/dm-sflc/src/legacy/sysfs.c
@@ -82,12 +82,12 @@ static const struct attribute_group sflegc_device_attr_group = {
 
 int sflegc_sysfs_add_device(sflegc_Device *dev)
 {
-	return sysfs_create_group(dev->sd_base.kobj, &sflegc_device_attr_group);
+	return sysfs_create_group(&dev->sd_base.kobj, &sflegc_device_attr_group);
 }
 
 void sflegc_sysfs_remove_device(sflegc_Device *dev)
 {
-	sysfs_remove_group(dev->sd_base.kobj, &sflegc_device_attr_group);
+	sysfs_remove_group(&dev->sd_base.kobj, &sflegc_device_attr_group);
 }
 
 
@@ -124,10 +124,10 @@ static const struct attribute_group sflegc_volume_attr_group = {
 
 int sflegc_sysfs_add_volume(sflegc_Volume *vol)
 {
-	return sysfs_create_group(vol->sv_base.kobj, &sflegc_volume_attr_group);
+	return sysfs_create_group(&vol->sv_base.kobj, &sflegc_volume_attr_group);
 }
 
 void sflegc_sysfs_remove_volume(sflegc_Volume *vol)
 {
-	sysfs_remove_group(vol->sv_base.kobj, &sflegc_volume_attr_group);
+	sysfs_remove_group(&vol->sv_base.kobj, &sflegc_volume_attr_group);
 }
diff --git a/dm-sflc/src/legacy/volume/fmap.c b/dm-sflc/src/legacy/volume/fmap.c
index c0ca78c..7f924ae 100644
--- a/dm-sflc/src/legacy/volume/fmap.c
+++ b/dm-sflc/src/legacy/volume/fmap.c
@@ -137,7 +137,7 @@ int sflegc_vol_loadFmap(sflegc_Volume * vol)
         }
 
         /* Starting block of the position map (skip the DMB, the previous volume headers, and the VMB) */
-        sector = 1 + (vol->vol_idx * dev->vol_header_size) + 1;
+        sector = 1 + (vol->sv_base.vol_idx * dev->vol_header_size) + 1;
         /* Starting LSI in the fmap */
         lsi = 0;
 
@@ -182,7 +182,7 @@ int sflegc_vol_loadFmap(sflegc_Volume * vol)
                                 vol->fmap[lsi] = psi;
                                 /* Also add it to the device's rmap and to the count, if LSI is actually mapped */
                                 if (psi != SFLEGC_VOL_FMAP_INVALID_PSI) {
-                                        sflegc_dev_markPsiTaken(dev, psi, vol->vol_idx);
+                                        sflegc_dev_markPsiTaken(dev, psi, vol->sv_base.vol_idx);
                                         vol->mapped_slices += 1;
                                 }
 
@@ -247,7 +247,7 @@ int sflegc_vol_storeFmap(sflegc_Volume * vol)
         }
 
         /* Starting block of the position map (skip the DMB, the previous volume headers, and the VMB) */
-        sector = 1 + (vol->vol_idx * dev->vol_header_size) + 1;
+        sector = 1 + (vol->sv_base.vol_idx * dev->vol_header_size) + 1;
         /* Starting LSI in the fmap */
         lsi = 0;
 
@@ -366,7 +366,7 @@ static s32 sflegc_vol_mapSlice(sflegc_Volume * vol, u32 lsi, int op)
         vol->fmap[lsi] = psi;
         vol->mapped_slices += 1;
         /* And in the device's rmap */
-        sflegc_dev_markPsiTaken(dev, psi, vol->vol_idx);
+        sflegc_dev_markPsiTaken(dev, psi, vol->sv_base.vol_idx);
 
         /* Unlock both maps */
         mutex_unlock(&dev->slices_lock);
diff --git a/dm-sflc/src/legacy/volume/volume.c b/dm-sflc/src/legacy/volume/volume.c
index 8c62e1f..f37623d 100644
--- a/dm-sflc/src/legacy/volume/volume.c
+++ b/dm-sflc/src/legacy/volume/volume.c
@@ -32,6 +32,7 @@
 #include "legacy/volume/volume.h"
 #include "legacy/utils/string.h"
 #include "legacy/log/log.h"
+#include "sflc.h"
 
 #include <linux/vmalloc.h>
 
@@ -128,13 +129,11 @@ struct sflc_volume_base *sflegc_vol_ctr(struct sflc_device_base *sd_base,
 	vol->mapped_slices = 0;
 
 	/* Initialise fmap */
-	pr_notice("Volume opening for volume %s: loading fmap from header\n", vol->vol_name);
 	err = sflegc_vol_loadFmap(vol);
 	if (err) {
 		pr_err("Could not load position map; error %d\n", err);
 		goto err_load_fmap;
 	}
-	pr_debug("Successfully loaded position map for volume %s\n", vol->vol_name);
 
 
 	/* Tell DM we want one SFLC sector at a time */
@@ -157,7 +156,7 @@ err_load_fmap:
 err_alloc_fmap:
 	sflegc_sk_destroyContext(vol->skctx);
 err_create_skctx:
-	sflegc_dev_removeVolume(vol->dev, vol->vol_idx);
+	sflegc_dev_removeVolume(vol->dev, vol->sv_base.vol_idx);
 err_add_to_dev:
 	sflegc_sysfs_remove_volume(vol);
 err_sysfs:
@@ -170,7 +169,7 @@ err_alloc_vol:
 }
 
 /* Removes the volume from the device and frees it. */
-void sflite_vol_dtr(struct sflc_volume_base *sv_base)
+void sflegc_vol_dtr(struct sflc_volume_base *sv_base)
 {
 	sflegc_Volume *vol = container_of(sv_base, sflegc_Volume, sv_base);
 	int err;
@@ -187,7 +186,7 @@ void sflite_vol_dtr(struct sflc_volume_base *sv_base)
 	sflegc_sk_destroyContext(vol->skctx);
 
 	/* Remove from device */
-	sflegc_dev_removeVolume(vol->dev, vol->vol_idx);
+	sflegc_dev_removeVolume(vol->dev, vol->sv_base.vol_idx);
 
 	/* Destroy sysfs entries */
 	sflegc_sysfs_remove_volume(vol);
diff --git a/dm-sflc/src/lite/device.c b/dm-sflc/src/lite/device.c
index 55ff28e..cd10ef0 100644
--- a/dm-sflc/src/lite/device.c
+++ b/dm-sflc/src/lite/device.c
@@ -26,6 +26,7 @@
 #include <linux/random.h>
 #include <linux/minmax.h>
 #include "sflc_lite.h"
+#include "sflc.h"
 
 
 
@@ -174,7 +175,6 @@ bad_bioset:
 bad_prmslices:
 	vfree(sdev->slices_ofld);
 bad_ofld:
-bad_lookup:
 bad_parse:
 	sflc_dev_base_exit(&sdev->sd_base);
 bad_base:
diff --git a/dm-sflc/src/lite/sysfs.c b/dm-sflc/src/lite/sysfs.c
index 3c6d72f..6c15b66 100644
--- a/dm-sflc/src/lite/sysfs.c
+++ b/dm-sflc/src/lite/sysfs.c
@@ -34,16 +34,16 @@
 
 static ssize_t tot_slices_show(struct kobject *kobj, struct kobj_attribute *kattr, char *buf)
 {
-	struct sflc_device *top_dev = container_of(kobj, struct sflc_device, kobj);
-	struct sflite_device *sdev = top_dev->sflite_dev;
+	struct sflc_device_base *sd_base = container_of(kobj, struct sflc_device_base, kobj);
+	struct sflite_device *sdev = container_of(sd_base, struct sflite_device, sd_base);
 
 	return sysfs_emit(buf, "%u\n", sdev->tot_slices);
 }
 
 static ssize_t free_slices_show(struct kobject *kobj, struct kobj_attribute *kattr, char *buf)
 {
-	struct sflc_device *top_dev = container_of(kobj, struct sflc_device, kobj);
-	struct sflite_device *sdev = top_dev->sflite_dev;
+	struct sflc_device_base *sd_base = container_of(kobj, struct sflc_device_base, kobj);
+	struct sflite_device *sdev = container_of(sd_base, struct sflite_device, sd_base);
 	int ret;
 
 	if (mutex_lock_interruptible(&sdev->slices_lock))
@@ -84,8 +84,8 @@ void sflite_sysfs_remove_device(struct sflite_device *sdev)
 
 static ssize_t mapped_slices_show(struct kobject *kobj, struct kobj_attribute *kattr, char *buf)
 {
-	struct sflc_volume *top_vol = container_of(kobj, struct sflc_volume, kobj);
-	struct sflite_volume *svol = top_vol->sflite_vol;
+	struct sflc_volume_base *sv_base = container_of(kobj, struct sflc_volume_base, kobj);
+	struct sflite_volume *svol = container_of(sv_base, struct sflite_volume, sv_base);
 	int ret;
 
 	if (mutex_lock_interruptible(&svol->posmap_lock))
diff --git a/dm-sflc/src/lite/volume.c b/dm-sflc/src/lite/volume.c
index 3df5edd..26717b9 100644
--- a/dm-sflc/src/lite/volume.c
+++ b/dm-sflc/src/lite/volume.c
@@ -23,6 +23,7 @@
 
 #include <linux/vmalloc.h>
 #include "sflc_lite.h"
+#include "sflc.h"
 
 
 /**
diff --git a/dm-sflc/src/sflc.c b/dm-sflc/src/sflc.c
index 1a7e802..76b0f0e 100644
--- a/dm-sflc/src/sflc.c
+++ b/dm-sflc/src/sflc.c
@@ -32,14 +32,22 @@
 #include <linux/delay.h>
 
 
-// Global variables
+/* Global variables */
+
+// A set of algorithms for each Shufflecake mode, in the same order as the modes.
+struct sflc_mode_ops *sflc_all_mode_ops[SFLC_NR_MODES] = {
+	&sflc_legacy_ops,
+	&sflc_lite_ops
+};
+
+// Global array of base device objects
 DEFINE_MUTEX(sflc_alldevs_lock);
-struct sflc_device **sflc_alldevs = NULL;
+struct sflc_device_base **sflc_alldevs = NULL;
 u32 sflc_free_devid = 0;	/* The lowest free devID */
 
 
 /* Add a device to the global array, and advance next_dev_id */
-static int sflc_add_device_global(u32 dev_id, struct sflc_device *sdev)
+static int sflc_add_device_global(u32 dev_id, struct sflc_device_base *sd_base)
 {
 	int i;
 
@@ -54,7 +62,7 @@ static int sflc_add_device_global(u32 dev_id, struct sflc_device *sdev)
 		return -EINVAL;
 	}
 	// Add to the global array, and advance free_devid
-	sflc_alldevs[dev_id] = sdev;
+	sflc_alldevs[dev_id] = sd_base;
 	for (i = sflc_free_devid; i < SFLC_MAX_DEVS && sflc_alldevs[i]; i++);
 	sflc_free_devid = i;
 
@@ -86,10 +94,12 @@ static void sflc_remove_device_global(u32 dev_id)
  */
 static int sflc_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
+	u32 mode;
+	struct sflc_mode_ops *mode_ops;
 	u32 dev_id;
 	u32 vol_idx;
-	struct sflc_device *sdev;
-	struct sflc_volume *svol;
+	struct sflc_device_base *sd_base;
+	struct sflc_volume_base *sv_base;
 	int err;
 
 	/* Parse arguments */
@@ -97,6 +107,10 @@ static int sflc_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		ti->error = "Invalid argument count";
 		return -EINVAL;
 	}
+	if (sscanf(argv[0], "%u", &mode) != 1) {
+		ti->error = "Could not decode mode";
+		return -EINVAL;
+	}
 	if (sscanf(argv[1], "%u", &dev_id) != 1) {
 		ti->error = "Could not decode device ID";
 		return -EINVAL;
@@ -106,6 +120,10 @@ static int sflc_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		return -EINVAL;
 	}
 	/* Sanity checks */
+	if (mode >= SFLC_NR_MODES) {
+		ti->error = "Mode out of bounds";
+		return -EINVAL;
+	}
 	if (dev_id >= SFLC_MAX_DEVS) {
 		ti->error = "Device ID out of bounds";
 		return -EINVAL;
@@ -114,16 +132,18 @@ static int sflc_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		ti->error = "Volume index out of bounds";
 		return -EINVAL;
 	}
+	/* Grab the correct mode */
+	mode_ops = sflc_all_mode_ops[mode];
 
 	/* Create device, if this is the first volume, otherwise retrieve it */
 	if (vol_idx == 0) {
-		sdev = sflc_dev_create(ti, argc, argv);
-		if (IS_ERR(sdev)) {
+		sd_base = mode_ops->dev_ctr(ti, argc, argv);
+		if (IS_ERR(sd_base)) {
 			ti->error = "Could not instantiate device";
-			return PTR_ERR(sdev);
+			return PTR_ERR(sd_base);
 		}
 		/* Insert in global array */
-		err = sflc_add_device_global(dev_id, sdev);
+		err = sflc_add_device_global(dev_id, sd_base);
 		if (err) {
 			ti->error = "Could not add device to global array";
 			goto bad_dev_global;
@@ -131,26 +151,26 @@ static int sflc_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	} else {
 		if (mutex_lock_interruptible(&sflc_alldevs_lock))
 			return -ERESTARTSYS;
-		sdev = sflc_alldevs[dev_id];
+		sd_base = sflc_alldevs[dev_id];
 		mutex_unlock(&sflc_alldevs_lock);
 
-		if (!sdev) {
+		if (!sd_base) {
 			ti->error = "Could not find device with specified ID";
 			return -EINVAL;
 		}
 	}
 
 	/* Create volume */
-	svol = sflc_vol_create(sdev, ti, argc, argv);
-	if (IS_ERR(svol)) {
+	sv_base = mode_ops->vol_ctr(sd_base, ti, argc, argv);
+	if (IS_ERR(sv_base)) {
 		ti->error = "Could not instantiate volume";
-		err = PTR_ERR(svol);
+		err = PTR_ERR(sv_base);
 		goto bad_vol_create;
 	}
 	/* We expect ->ctr() calls to be strictly sequential, so we don't need locking */
-	sdev->nr_volumes++;
+	sd_base->nr_volumes++;
 
-	ti->private = svol;
+	ti->private = sv_base;
 
 	return 0;
 
@@ -159,7 +179,7 @@ bad_vol_create:
 	if (vol_idx == 0) {
 		sflc_remove_device_global(dev_id);
 bad_dev_global:
-		sflc_dev_destroy(sdev);
+		mode_ops->dev_dtr(sd_base);
 	}
 	return err;
 }
@@ -168,16 +188,16 @@ bad_dev_global:
 /* Destroy volume and, if needed, the underlying device */
 static void sflc_dtr(struct dm_target *ti)
 {
-	struct sflc_volume *svol = ti->private;
-	struct sflc_device *sdev = svol->sdev;
+	struct sflc_volume_base *sv_base = ti->private;
+	struct sflc_device_base *sd_base = sv_base->sd_base;
 
-	sflc_vol_destroy(svol);
+	sv_base->ops->vol_dtr(sv_base);
 	/* We expect ->dtr() calls to be strictly sequential, so we don't need locking */
-	sdev->nr_volumes--;
+	sd_base->nr_volumes--;
 
-	if (sdev->nr_volumes == 0) {
-		sflc_remove_device_global(sdev->dev_id);
-		sflc_dev_destroy(sdev);
+	if (sd_base->nr_volumes == 0) {
+		sflc_remove_device_global(sd_base->dev_id);
+		sd_base->ops->dev_dtr(sd_base);
 	}
 
 	return;
@@ -186,21 +206,21 @@ static void sflc_dtr(struct dm_target *ti)
 
 static int sflc_map(struct dm_target *ti, struct bio *bio)
 {
-	struct sflc_volume *svol = ti->private;
-	return svol->tt->map(ti, bio);
+	struct sflc_volume_base *sv_base = ti->private;
+	return sv_base->ops->map(ti, bio);
 }
 
 static void sflc_io_hints(struct dm_target *ti, struct queue_limits *limits)
 {
-	struct sflc_volume *svol = ti->private;
-	svol->tt->io_hints(ti, limits);
+	struct sflc_volume_base *sv_base = ti->private;
+	return sv_base->ops->io_hints(ti, limits);
 	return;
 }
 
 static int sflc_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
 {
-	struct sflc_volume *svol = ti->private;
-	return svol->tt->iterate_devices(ti, fn, data);
+	struct sflc_volume_base *sv_base = ti->private;
+	return sv_base->ops->iterate_devices(ti, fn, data);
 }
 
 
diff --git a/dm-sflc/src/sflc.h b/dm-sflc/src/sflc.h
index ed206c1..a3459ca 100644
--- a/dm-sflc/src/sflc.h
+++ b/dm-sflc/src/sflc.h
@@ -38,7 +38,7 @@
  */
 
 /* Every mode provides a full set of algorithms */
-struct sflc_mode_ops **sflc_mode_ops;
+extern struct sflc_mode_ops *sflc_all_mode_ops[SFLC_NR_MODES];
 
 /* Array of all open devices */
 extern struct mutex sflc_alldevs_lock;
diff --git a/dm-sflc/src/sflc_constants.h b/dm-sflc/src/sflc_constants.h
index c978796..c608581 100644
--- a/dm-sflc/src/sflc_constants.h
+++ b/dm-sflc/src/sflc_constants.h
@@ -45,6 +45,7 @@
 /* Each device can be formatted and used with a mode of choice, irrespective of the other devices */
 #define SFLC_MODE_LEGACY 0
 #define SFLC_MODE_LITE 1
+#define SFLC_NR_MODES 2
 
 
 /* Max number of volumes per device */
diff --git a/dm-sflc/src/sflc_types.h b/dm-sflc/src/sflc_types.h
index 2415229..d2927cd 100644
--- a/dm-sflc/src/sflc_types.h
+++ b/dm-sflc/src/sflc_types.h
@@ -54,8 +54,6 @@
 #include <linux/device-mapper.h>
 
 #include "sflc_constants.h"
-#include "legacy/sflc_legacy.h"
-#include "lite/sflc_lite.h"
 
 
 /*

From 1a775e9a44e978f9611e52fef25903239f6413de Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Wed, 2 Oct 2024 22:21:57 +0200
Subject: [PATCH 10/12] Add symlink to sflc_types.h

---
 dm-sflc/bin/sflc_types.h | 1 +
 1 file changed, 1 insertion(+)
 create mode 120000 dm-sflc/bin/sflc_types.h

diff --git a/dm-sflc/bin/sflc_types.h b/dm-sflc/bin/sflc_types.h
new file mode 120000
index 0000000..d320fe2
--- /dev/null
+++ b/dm-sflc/bin/sflc_types.h
@@ -0,0 +1 @@
+../src/sflc_types.h
\ No newline at end of file

From ad958dd62bc2432323081468b8b7c6bae7d5ed95 Mon Sep 17 00:00:00 2001
From: = <elianzuoni@gmail.com>
Date: Wed, 2 Oct 2024 22:46:33 +0200
Subject: [PATCH 11/12] Adapt FLUSH behaviour of legacy

---
 dm-sflc/src/legacy/target.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/dm-sflc/src/legacy/target.c b/dm-sflc/src/legacy/target.c
index a95d60d..52970b4 100644
--- a/dm-sflc/src/legacy/target.c
+++ b/dm-sflc/src/legacy/target.c
@@ -77,17 +77,19 @@ static int sflegc_tgt_map(struct dm_target *ti, struct bio *bio)
 	struct sflc_volume_base *sv_base = ti->private;
 	sflegc_Volume *vol = container_of(sv_base, sflegc_Volume, sv_base);
 
-        /* If no data, just quickly remap the sector and the block device (no crypto) */
-	/* TODO: this is dangerous for deniability, will need more filtering */
-        if (unlikely(!bio_has_data(bio))) {
-        	pr_debug("No-data bio: bio_op = %d", bio_op(bio));
-                err = sflegc_vol_remapBioFast(vol, bio);
-		if (err) {
-			pr_err("Could not remap bio; error %d\n", err);
+        /* Copied from sflc_lite */
+	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
+		/* Has to be empty though */
+		if (bio_sectors(bio)) {
+			DMWARN("Non-empty flush request!");
+			//msleep(3000);
 			return DM_MAPIO_KILL;
 		}
-                return DM_MAPIO_REMAPPED;
-        }
+//		DMWARN("REQ_PREFLUSH empty (phew), sector: %llu", bio->bi_iter.bi_sector);
+//		msleep(100);
+		bio_set_dev(bio, vol->dev->bdev->bdev);
+		return DM_MAPIO_REMAPPED;
+	}
 
 	/* At this point, the bio has data. Do a few sanity checks */
 	/* TODO: I think we can get rid of all of them */

From 2d5cb4c74a78ab2cb9b8b63c16a341cf74738ebb Mon Sep 17 00:00:00 2001
From: Tommaso Gagliardoni <nomail@nomail.nomail>
Date: Sun, 13 Oct 2024 12:08:26 +0200
Subject: [PATCH 12/12] chore:Prepare release v0.5.1

---
 CHANGELOG.md                                  |  12 ++++++
 README.md                                     |  37 ++++--------------
 dm-sflc/src/sflc_constants.h                  |   4 +-
 .../images/badges/badge_version_0.5.0.png     | Bin 2410 -> 0 bytes
 .../images/badges/badge_version_0.5.1.png     | Bin 0 -> 2241 bytes
 resources/images/badges/badges.svg            |   8 ++--
 6 files changed, 25 insertions(+), 36 deletions(-)
 delete mode 100644 resources/images/badges/badge_version_0.5.0.png
 create mode 100644 resources/images/badges/badge_version_0.5.1.png

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c4434fc..75a3a64 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  - Global constants fully shared among components through `sflc_constants.h`.
 
 
+## [0.5.1] - 2024-10-13
+
+### Refactored
+
+ - Reorganized interface between dispatcher and dm-legacy through pointers to functions.
+
+### Fixed
+
+ - Fixed debug error message when reading unallocated slices on dm-legacy.
+
+
 ## [0.5.0] - 2024-09-01
 
 ### Added
@@ -37,6 +48,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  - Changed all occurrences of "Shufflecake Old" to "Shufflecake Legacy", including code paths and variables.
  - Reordered entries in CHANGELOG.md with sections following the order Added -> Changed -> Fixed -> Refactored -> Removed.
 
+
 ## [0.4.5] - 2024-06-03
 
 ### Changed
diff --git a/README.md b/README.md
index beee2f9..863150c 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 [![Status](resources/images/badges/badge_status_active.png)](https://codeberg.org/shufflecake/shufflecake-c)&nbsp;
-[![Version](resources/images/badges/badge_version_0.5.0.png)](https://codeberg.org/shufflecake/shufflecake-c/releases/tag/v0.5.0)&nbsp;
+[![Version](resources/images/badges/badge_version_0.5.1.png)](https://codeberg.org/shufflecake/shufflecake-c/releases/tag/v0.5.1)&nbsp;
 [![License](resources/images/badges/badge_license_gplv2plus.png)](https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html)&nbsp;
 [![Docs researchpaper](resources/images/badges/badge_docs_researchpaper.png)](https://eprint.iacr.org/2023/1529)&nbsp;
 [![Website](resources/images/badges/badge_web_shufflecakedotnet.png)](https://shufflecake.net/)&nbsp;
@@ -12,7 +12,7 @@
 
 
 
-# Shufflecake - Full C Implementation - v0.5.0
+# Shufflecake - Full C Implementation - v0.5.1
 
 _Shufflecake_ is a plausible deniability (hidden storage) layer for Linux. You can consider Shufflecake a spiritual successor of tools like TrueCrypt and VeraCrypt, but vastly improved, both in terms of security and functionality. Official website: <https://www.shufflecake.net>.
 
@@ -265,6 +265,11 @@ Both methods works with the `init` action, and we do not have current plans to c
 
 Please see the file `CHANGELOG.md` for a detailed history of changes.
 
+### [0.5.1] - 2024-10-13
+
+ - Reorganized interface between dispatcher and dm-legacy through pointers to functions.
+ - Fixed debug error message when reading unallocated slices on dm-legacy.
+
 ### [0.5.0] - 2024-09-01
 
  - BREAKING CHANGE: major rewrite, bugfixes, introduced Shufflecake "Lite" as a default mode of operation.
@@ -273,34 +278,6 @@ Please see the file `CHANGELOG.md` for a detailed history of changes.
 
  - Fixed a compile error on some versions of LTS kernels.
  - Fixed segmentation fault when opening an already opened device.
- 
-### [0.4.4] - 2023-12-31
-
- - Fixed a memory allocation error on large devices.
- 
-### [0.4.3] - 2023-11-29
-
- - Fixed compile error on recent kernel versions.
- 
-### [0.4.2] - 2023-11-28
-
- - Fixed persistent slice allocation ambiguity after a volume corruption by allocating fresh slices for the corrupted volume. This is done in order to help external recovery tools (e.g. RAID).
- - Various bugfixes.
-
-### [0.4.1] - 2023-07-30
-
- - Fixed and improved benchmark scripts.
- - Fixed mistake in drawing of header layout in `doc`.
-
-### [0.4.0] - 2023-07-24
-
-- BREAKING CHANGE: slightly modified header field format, removing redundant data and making it adherent to documentation.
-- Implemented reference slice allocation algorithm with much faster performance.
-- Added actions `checkpwd` and `changepwd`.
-- Password is now read in a secure shell during `open`.
-- Added benchmark suite.
-- Fixed bugs in action `close` and option `--skip-randfill`.
-- Added `doc` (currently includes figure of Shufflecake headers structure).
 
 
 
diff --git a/dm-sflc/src/sflc_constants.h b/dm-sflc/src/sflc_constants.h
index c608581..e02d71d 100644
--- a/dm-sflc/src/sflc_constants.h
+++ b/dm-sflc/src/sflc_constants.h
@@ -33,8 +33,8 @@
 
 #define SFLC_VER_MAJOR 0
 #define SFLC_VER_MINOR 5
-#define SFLC_VER_REVISION 0
-#define SFLC_VER_SPECIAL "rc1"
+#define SFLC_VER_REVISION 1
+#define SFLC_VER_SPECIAL ""
 
 #define STRINGIFY0(s) # s
 #define STRINGIFY(s) STRINGIFY0(s)
diff --git a/resources/images/badges/badge_version_0.5.0.png b/resources/images/badges/badge_version_0.5.0.png
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diff --git a/resources/images/badges/badges.svg b/resources/images/badges/badges.svg
index 254bb97..32b9e6a 100644
--- a/resources/images/badges/badges.svg
+++ b/resources/images/badges/badges.svg
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      inkscape:zoom="2.7438272"
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-     inkscape:cy="198.26321"
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